Two-Wire Open Line

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
3-3 The five types of transmission mediums that we will discuss in this chapter include PARALLEL-LINE, TWISTED PAIR, SHIELDED PAIR, COAXIAL LINE, and WAVEGUIDES. The use of a particular line depends, among other things, on the applied frequency, the power-handling capabilities, and the type of installation. NOTE: In the following paragraphs, we will mention LOSSES several times. We will discuss these losses more thoroughly under "LOSSES IN TRANSMISSION LINES." Two-Wire Open Line One type of parallel line is the TWO-WIRE OPEN LINE illustrated in figure 3-2. This line consists of two wires that are generally spaced from 2 to 6 inches apart by insulating spacers. This type of line is most often used for power lines, rural telephone lines, and telegraph lines. It is sometimes used as a transmission line between a transmitter and an antenna or between an antenna and a receiver. An advantage of this type of line is its simple construction. The principal disadvantages of this type of line are the high radiation losses and electrical noise pickup because of the lack of shielding. Radiation losses are produced by the changing fields created by the changing current in each conductor. Figure 3-2.—Parallel two-wire line. Another type of parallel line is the TWO-WIRE RIBBON (TWIN LEAD) illustrated in figure 3-3. This type of transmission line is commonly used to connect a television receiving antenna to a home television set. This line is essentially the same as the two-wire open line except that uniform spacing is assured by embedding the two wires in a low-loss dielectric, usually polyethylene. Since the wires are embedded in the thin ribbon of polyethylene, the dielectric space is partly air and partly polyethylene. Figure 3-3.—Two-wire ribbon type line.

Electrical News
The Growing Popularity of Emulation Design Datacenters
If loaded with enough resources, a modern emulator can be...
3D Tetrapod Quantum Dots Outperform
Tetrapod quantum dots offer brighter more colorful organic light emitting...
Can Samsung Get Qualcomm in LTE Market?
Samsung took the wraps off of a new LTE radio...
13 Things I Heard at Semicon West
Moore's Law slowing, Intel's foundry ramp-up, and a stealth mode...
Friday Quiz: All Oscilloscopes
Test your oscilloscope knowledge with the five questions submitted by...
Efficient Buildings to Be 100% Sensed
Sensing and control technology in the built environment will make...
Want Your Own Desktop PCB Printer?
The BreadBox PCB Printer controls things like time, mixing the...
IBM Turns PCM Cell Into Nano-Sized Lab
For the first time, researchers have provided actual crystallization and...
TSMC Said to Ship Apple SoCs
Taiwan Semiconductor Manufacturing Co. began shipping mobile processors to Apple...
Gartner Raises 2014 Chip Market Growth Forecast
The global chip market will be worth $336 billion in...
Menta's Embedded FPGA Fabric for SoC Designs
Using Menta's technology -- which is front-ended by Verific's parsers...
Honda Admits Software Problem, Recalls 175,000 Hybrids
For the first time, a carmaker has conceded that a...
Power Week: TSA – Say No to Powerless Devices
This week, the Transportation Security Administration announced a controversial new...
Qualcomm Snaps Up CSR's Imaging Team
Cellphone chipmaker Qualcomm is buying the imaging operations of CSR...
MCUs, Memory Balance Security, Performance
The need to secure devices at the MCU or SSD...
Bell Labs Hits 10 Gbit/s Broadband Over Copper
Alcatel-Lucent's Bell Labs invents new way to get broadband speeds...
Post-doc Position at University of Trento, Italy
The D3S group at the University of Trento, Italy, invites...
2-Year Chipmaking Equipment Spending Boom Coming
After years of underspending on chipmaking equipment, the semiconductor industry...
Patented Software, the Supreme Court & Abstract Idea Hearings
The Supreme Court has just ruled on the patentability of...
Nanotubes May Put IBM Watson in a Pocket
Stanford research describes progress in carbon nanotubes, noting the material's...

Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +